The landlord may withhold from the deposit only amounts reasonably necessary:(1) to remedy tenant defaults in the payment of rent or of other funds due to the landlord pursuant to an agreement; or(2) to restore the premises to their condition at the commencement of the tenancy, ordinary wear and tear excepted.

If it cannot be paid, the lender has the option of commencing foreclosure proceedings.

"83.50 In addition to any other disclosure required by law, the landlord, or a person authorized to enter into a rental agreement on the landlord's behalf, shall disclose in writing to the tenant, at or before the commencement of the tenancy, the name and address of the landlord or a person authorized to receive notices and demands in the landlord's behalf.

The list of actions includes things like, collect security deposit, collect first months rent, provide move-in condition form, receive signed move-in condition form back, periodic home inspections, receive proof of renters insurance, provide tenant with move-out procedures and signed copy of move-in/move out condition form, send tenant renewal notice, send tenant notice of non-renewal, etc. at the top of the spreadsheet we have four dates - date application completed, date applicant was approved, lease commencement date and lease expiration date.

Also as mentioned above in another comment, if and when the foreclosures due to the pandemic are commenced, those homes won't go to auction for at least 1 year but maybe much more because borrowers will most likely defend and drag it out. 

(Source: Section 337 of the Ca Code of Civil Procedures - The Time of Commencing Civil Actions)Personally, as Karl mentioned, I'd also give small claims court a consideration.  

If seller agrees to grant an extension on the closing date, then all parties would need to sign an addendum commencing the new closing date and provide it to the title agency.I agree Tom, pre-signing can cause more problems, especially if the deal falls through for whatever reason.

@James DeRoestMy personal views on the subject fall in the same realm as yourself, Tracy D.However, in our home jurisdictions evictions are relatively expedient (20 - 45 days) and inexpensive (the cost of having the sheriff come ... and not always that), such that we have never had cause to consider "buying off a tenant".However, if we were operating in a jurisdiction such as Greg's where the process of eviction commences with one, or more, $170.00 filing fees and can take several months, I can understand the temptation a landlord might have to pay ransom for her/his property.  

You may mail them the lease with the new commencement date in 30 days.

Also, was a permit pulled and a Notice of Commencement signed?